Study Question: Are progesterone vaginal pessaries 400 mg twice a day (bid) non-inferior to progesterone vaginal gel (90 mg) once a day (od) in the primary endpoint of clinical pregnancy rate after 38 days of luteal phase support in women undergoing in vitro fertilisation (IVF)?
Summary Answer: Non-inferiority of progesterone vaginal pessaries 400 mg bid to progesterone 8% vaginal gel (90 mg od) was shown for clinical pregnancy rate after 38 days of luteal phase support.
What Is Known Already: To maximise successful embryo transfer after IVF, additionally administered progesterone is used for proper endometrium transformation in the luteal phase. Vaginally administered progesterone results in adequate secretory transformation of the endometrium.